Assets and Liabilities Related to Insurance Risks (Details) - USD ($) $ in Thousands	Dec. 31, 2015	Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Current assets:
Insurance subsidiary investments	$ 106,638	$ 99,951
Reinsurance recoverables	10,302	7,376
Other	100	100
Insurance Risks Assets Current, Total	117,040	107,427
Non-current asset:
Insurance subsidiary investments	204,498	166,045
Reinsurance and other recoverables	177,330	155,436
Deposits	8,317	5,307
Other	38	38
Insurance Risks Assets Non Current, Total	390,183	326,826
Insurance Risks Assets, Total	507,223	434,253
Liabilities:
Current	112,869	103,939
Non-current	469,352	393,071
Allowance For Insurance Risks, Total	582,221	497,010	$ 494,860	$ 484,079
Professional Malpractice Liability Insurance
Current assets:
Insurance subsidiary investments	61,889	63,183
Reinsurance recoverables	9,282	7,376
Insurance Risks Assets Current, Total	71,171	70,559
Non-current asset:
Insurance subsidiary investments	82,207	84,210
Reinsurance and other recoverables	90,387	81,722
Deposits	3,980	3,879
Insurance Risks Assets Non Current, Total	176,574	169,811
Insurance Risks Assets, Total	247,745	240,370
Liabilities:
Current	64,099	64,137
Non-current	263,273	243,614
Allowance For Insurance Risks, Total	327,372	307,751	307,223	290,718
Workers compensation
Current assets:
Insurance subsidiary investments	44,749	36,768
Reinsurance recoverables	1,020
Other	100	100
Insurance Risks Assets Current, Total	45,869	36,868
Non-current asset:
Insurance subsidiary investments	122,291	81,835
Reinsurance and other recoverables	86,943	73,714
Deposits	4,337	1,428
Other	38	38
Insurance Risks Assets Non Current, Total	213,609	157,015
Insurance Risks Assets, Total	259,478	193,883
Liabilities:
Current	48,770	39,802
Non-current	206,079	149,457
Allowance For Insurance Risks, Total	$ 254,849	$ 189,259	$ 187,637	$ 193,361